1. Technical Field
The technology disclosed herein relates to a shutter drive device, a shutter device, and an imaging device.
2. Background Information
A shutter device for adjusting the exposure of an imaging element is installed in an imaging device. The imaging element converts light into an electrical charge, so light that would be incident on the imaging element must be blocked off while the electrical change is being read as image data from the imaging element. Therefore, light that would be incident on the imaging element is usually blocked by a shutter device while image data is being read from the imaging element.
Meanwhile, most imaging devices employ a live-view function in which a real-time image of the subject is displayed on a display component. In live view, light must be incident on the imaging device, so the shutter device must be kept in an open state.
However, with the normally-closed type of shutter device that is generally used, the electricity must be sent to an electromagnet to hold the shutter curtain in the open position in order to maintain the open state of the shutter device. The longer electricity is sent to the electromagnet, the more power consumption rises, so employing a normally-closed type of shutter device in an imaging device having a live-view function is undesirable from the standpoint of power consumption.
In view of this, a normally-open type of shutter device has been proposed that takes the live-view function into account (see, for example, Japanese Laid-Open Patent Application 2004-061865).